Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cuu tre » cua tre, cau treo
dan vat » dang vat, van vat, dan va
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
ty hang » ly hang, thi hang, thu hang
cam tuc » cam xuc, cam tu, nam thuc
ve cam » ve cham, ve cac, va cam
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((ty xang) or (ty hang)) xa hoi. hieu ve cam tuc va dan vat ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty xang) OR (ty hang)) xa hoi. hieu ve cam tuc va dan vat ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty xang) or (ty hang)) xa hoi. hieu ve cam tuc va dan vat ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty xang) or (ty hang)) xa hoi. hieu ve cam tuc va dan vat ((cuu tre) OR (cau tren))*.